The Duke of Lu was a title held by rulers of the ancient Chinese state of Lu, which existed during the Spring and Autumn period of Chinese history. The state was located in what is now Shandong province and was known for its cultural and political significance. The Duke of Lu played a crucial role in the governance and military affairs of the state, often engaging in alliances and conflicts with neighboring states. One of the most famous Dukes of Lu was Duke Jing of Lu, who ruled during the 5th century BCE. His reign is noted for the promotion of Confucianism, as the philosopher Confucius was born in Lu and served as a minister in the court. The Duke's support of Confucian ideals contributed to the lasting influence of these teachings in Chinese culture.